Latest data shows Philae may have been saved by a crater rim

The Philae lander was released by the European Space Agency’s (ESA) Rosetta craft on November 12th as it orbited comet 67P/Churyumov-Gerasimenko. The plan was for Philae to float down toward the surface and attach itself with harpoons before doing some science. The landing went mostly to plan, except the whole harpoon thing. After landing, Philae bounced a few times, but now the team thinks the lander might have been saved when it grazed a crater rim.

A new analysis of data gathered by the ROMAP (Rosetta Lander Magnetometer and Plasma Monitor) instrument on board Philae points to a lucky break during its tumultuous arrival on P67. Based on the magnetic field data from ROMAP, the ESA has reconstructed a preliminary timeline of the event. At 16:03 GMT Philae made contact with the surface and the harpoons failed to deploy. This was the big bounce — while ESA administrators were having press conferences and making speeches, Philae was floating free.

Philae reached an altitude of about 1km before descending again, at 16:20 GMT it made contact for the second time. This is the impact that was different than the others — it only grazed the surface with one of its legs, which sent it tumbling. The nature of the surface feature it collided with is up for debate, but the team has speculated that the rim of a crater is the best bet. At 17:25 GMT Philae landed again with one foot, then with all three feet. Finally, it floated a bit more and came to rest several minutes later. If it hadn’t grazed the surface on its second contact, the team suggests it might have ended up much farther off course and completely covered in shadows.

As it currently stands, Philae is in a poor position to gather light with its solar panels. Only three of its six panels get any light at all, and those only receive an hour or so per 12.4 hour comet day. After doing its initial experiments, the ESA decided to place Philae in hibernation mode in hopes that as the comet nears the sun, it might receive enough light to operate again. It’s hard to know for sure, though. Mission scientists haven’t been able to find its exact location yet.

Reconstructing the landing isn’t just about mapping out the bounces Philae took, it’s another piece of the puzzle in the quest to find the sleeping lander. Data from both Rosetta and Philae is being used to narrow the search. Finding its final resting place will help the ESA estimate when and if Philae will ever wake up.